Pneumatic tool.



H. E. LE GENDRE.

PNEUMATIC TOOL.

APPLICATION FILED 111N312, 1913.

1,083,369. 7 Patented Jan. 6, 1914,

HENRY E. LE GENDRE, OF CRESKILL, NEW JERSEY.

PNEUMATIC TOOL.

T 0 all whom it may concern:

Be it known that I, HENRY E. -LE GEN- DRE, a citizen of the United States, and a resident of Creskill, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Pneumatic Tools, of which the following is a specification.

The present invention relates to pneu mat-ic tools and has for one of its objects means whereby the same tool may be used to obtain both power strokes and finishing strokes, that is, strokes of varying intensity.

Another object of the invention is to produce a smooth-working eflicient tool.

Accordingly one feature of the invention resides in providing means whereby the stroke in the cylinder of the piston may be varied to produce blows of a difierent character, without -varying the amount of motive fluid admitted to the tool. The specific means for carrying this into eilect reside in a reversible member fitted within the cylinder and which in one position will permit the piston to travel a certain distanoe, and in another position will permit the piston to travel only a limited distance. In other words, the reversible member by its position varies the effective length of the cylinder.

The invention further consists in a new method and means for actuating the piston, which consists in alternately admitting motive fluid to and exhausting said fluid from one side of the piston, and in continuously admitting a limited amount of motive fluid to and intermittently exhausting said fluid from the other side of the piston.

In the accompanying drawings the invention is embodied in a concrete and preferred form, but changes in the disclosure shown may be made within the scope of the claims, without departing from the legitimate and intended scope of the invention.

In the said drawings: Figures 1 and 2 are vertical longitudinal sectional views taken at right angles to each other through the tool. Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 1. Fig. 4 is a similar view on the line 44 of Fig. 2. Fig. 5 is a vertical longitudinalsection, partly in elevation, of the upper end of a modified form of the tool.

Similar characters of reference indicate corresponding parts in the several views.

l indicates a casing or cylinder. of any Specification of Letters Patent.

Patented Jan. 6, 1914.

Application filed June 12, 1913. Serial No. 773,220.

suitable construction and 2 is a plunger or piston working within this casing. The form of tool shown in the drawings is of a. well-known construction and constitutes merely one embodiment of the invention. Motive fluid is led through the inlet 3 to the cross passages 4, down the longitudinal passages 5 to the openings 6, with which register at the proper moment the reduced portion 7 of the piston, permitting the air to fiow from the passages in the cylinder up through the passages 8 in the piston to the rear of the said piston, thereby causing it to move in one direct-ion. At the proper moment of the downward movement of the piston, the passages-6 are closed and the exhaust openings 9 are opened. These exhaust openings lead to the passages 10 in the casing communicating with exhaust opening 11. The passage 5 in theorising is carried down into the lower end of the 37 casing, where it terminates in a limited air inlet 12- which feeds motive fluid constantly into the lower portion of the casing. As the piston descends, the motive fluid will be ronstantly entering in limited quantities through the inlet 12, and will gradually form an air cushion, which of course becomes more pronounced as the piston descends. When the piston has descended far enough to uncover the exhaust openings 9, the air cushion formed below the piston will become effective to move the said piston in the opposite direction, and this mot-ion will then continue until the said piston uncovers the exhaust openings 13 communicating with the passage 10, whereby the air cushion produced by the air entering through the inlet 12 will be exhausted and the piston will commence its vforward stroke again.

The casing is provided with a shoulder or supporting ledge 14 near its upper end, on which shoulder rests a cup-shaped member 15 of an inside diameter equal to the general inside diameter of the casing, so that the piston in its upward travel may enter vvithin said cup-shaped member. This is illustrated particularly in Fig. 1 whn'e it will be noted that the member 15 is placed inn. position where it forms a continuation of the casing and therefore permi\ts the full stroke of the piston. By this means heavy powerful strokes can be obtained, particularly eilective in stone cutting tools when doing the rough preliminary cutting. In Fig. 2 the member 15 is shown in inverted or v 15 the inlet 3 bears upon vantage to be. able to have this member in REST AVAILABLE COP reversed osition, the bott0m'16 forming a closure w ich decreases the eflective length of the c linder and forms a surface against which the piston strikes, thereb limiting 6 its movement and reducing gent er strokes,

' whichare particu arly use u for the finalfinishin work.

It wil be apprehended that the strokes of two different sizes of tools may thus be 10 obtained by means of a single tool, and this without var ing the air pressure. It will also be not that the member is located below the transverse openings and that when in either p'oition the full air pressure from the said member 15.

It will be a parent that when it is desired to have t e 1on stroke of the piston, i the member 15 may be removed altogether from the tool, but it is an additional adthe tool, since it prevents this member bein lost or misplaced.

-. n Fig. 5 is shown a modified form of the invention, in which the memlmr'lz'i is formed 1 HS 3, Smooth-faced extension on the threaded 'men'iber 3. \Vhem so constructed it of course becomesnecessary when desiring a long stroke to substitute another threaded member, 3", as shownin Fig. l, the number '3 being devoid of this smooth extension. when the modification shown in Fig. 5 is used the passages l will be formed di ectly in the member 3 and will come opposite the passages 5 so that the incoming air may have con'muinication with 5:1 es 5.

hat is claimed, is:

1. in a valreless pneumatic too], a cylinder, a piston moaus for reeiprorat-in the piston, and means for varying the stro to of the piston by varying the vtiertiw length oi the rylindor.

9. In a pnrumatii: tool a ryliuder a is loin means for rouiprorating the piston \\Itllin the cylinder, and a rovorsiblu lnomla-r supportedwithin the oylindt-r for varying the eli'cutivo length of tho ovlindmn 3. In a vali'rloss pnvunndir took a ryliIu der having intake and exhaust ports, a piston, means for rei-iprot'atiug said .piston within tho t: \1limh r, a1ul means for varying the vtl'ovtivo length of tho oyhndor withd'ul rorroez]iondingly rhangring lhr position of rithrr inlaltn or exhaust ports.

Sigurd at Plymouth and \dalus streets borough of Brooklyn and lily of Non York in the would of l\'iu; s and Stallof New the said pas- 

